Physicochemical,Antioxidative, and Sensory Properties of Refined Rapeseed Oils

Physicochemical characteristics, antioxidant capacity (AC), and sensory quality of rapeseed oils available on the Polish market were analyzed and compared. The fatty acid composition (saturated fatty acids = 6.91–7.58%, monounsaturated fatty acids = 64.14–66.14%, and polyunsaturated fatty acids = 27.22–30.17%), color (T420 = 54.5–83.8%), amounts of free fatty acids (0.02–0.07%), primary (PV = 0.04–2.04 meq O₂ kg⁻¹) and secondary (AV = 1.02–3.21) oxidation products, phosphorus (0.38–1.62 mg kg⁻¹), chlorophyll (0.002–0.068 mg kg⁻¹), and polycyclic aromatic hydrocarbons (Σ4PAH = 0.00–2.50 μg kg⁻¹) in the commercial rapeseed oils meet the requirements of the European Food Regulation and Codex Alimentarius standards. Moreover, total phenolic content (TPC = 40.3–467.9 mg SA kg⁻¹) in the studied oils significantly differs from each other. However, the AC of rapeseed oils was analyzed using the novel iron oxide nanoparticle-based (IONP = 5552.1 − 18,510.2 μmol TE/100 g) method and the modified ferric reducing antioxidant power (FRAP = 55.7–280.3 μmol TE/100 g), cupric reducing AC (CUPRAC = 79.6–784.0 μmol TE/100 g), 2,2-diphenyl-1-picrylhydrazyl (DPPH = 185.7–516.7 μmol TE/100 g), and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS = 465.6–2142.6 μmol TE/100 g) assays. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for discrimination of the refined rapeseed oils based on fatty acid composition, physicochemical parameters, AC, and sensory properties.     

苍术及其麸炒品抗氧化活性研究

采用清除二苯代苦味酰基(DPPH)自由基、清除[2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)]二氨盐(ABTS)自由基和铁离子还原/抗氧化能力(FRAP)测定法对其挥发油和不同提取物进行抗氧化活性的研究。结果表明,生苍术乙酸乙酯提取物具有很好的抗氧化活性(DPPH方法:IC50=6.03μg/mL;ABTS方法:IC50=3.59μg/mL;FRAP方法:FRAP值=3186.67μmolTE/g),麸炒之后,其抗氧化活性显著下降。因而苍术抗氧化应生用。     

Antioxidant capacity of rapeseed meal and rapeseed oils enriched with meal extract

Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables: solvent polarity and temperature of the extraction process on the antioxidant capacity (AC) and total phenolics content (TPC) in meal rapeseed extracts. The mean AC and TPC results for meal ranged between 1181–9974 µmol TE/100 g and 73.8–814 mg sinapic acid/100 g of meal. The experimental results of AC and TPC were close to the predicted values calculated from the polynomial response surface models equations (R² = 0.9758 and 0.9603, respectively). The effect of solvent polarity on AC and TPC in the examined extracts was about 3.6 and 2.6 times greater, respectively, than the effect of processing temperature. The predicted optimum solvent polarity of ε = 78.3 and 63.8, and temperature of 89.4 and 74.2°C resulted in an AC of 10 014 µmol TE/100 g and TPC of 863 mg SAE/100 g meal, respectively. The phenolic profile of rapeseed meal was determined by an HPLC method. The main phenolics in rapeseed meal were sinapine and sinapic acid. Refined rapeseed oils were fortified with an extract – rich in polyphenols – obtained from rapeseed meal. The supplemented rapeseed oil had higher AC and TPC than the refined oil without addition of meal extracts. However, AC and TPC in the enriched oils decreased during storage. The TPC in the studied meal extracts and rapeseed oils correlated significantly (p<0.0000001) positively with their AC (R² = 0.9387). Practical applications: Many bioactive compounds extracted from rapeseed meal provide health benefits and have antioxidative properties. Therefore, it seems worth to consider the application of antioxidants extracted from the rapeseed meal for the production of rapeseed oils with potent AC. Moreover, antioxidants extracted from the rapeseed meal were added to refined rapeseed oil in order to enhance its AC. AC was then tested by FRAP assay. FRAP method is based on the reduction of the ferric tripyridyltriazine (Fe³⁺‐TPTZ) complex to the ferrous tripyridyltriazine (Fe²⁺‐TPTZ), and it is simple, fast, low cost, and robust method. FRAP method does not require specialized equipment and can be performed using automated, semi‐automatic, or manual methods. Therefore the proposed FRAP method can be employed by the fat industry laboratories to asses the AC of rapeseed oils and meal.     

Determination of polyphenols,tocopherols, and antioxidant capacity in virgin argan oil (Argania spinosa,Skeels)

This study establishes data on polyphenols, tocopherols, and antioxidant capacity (AC) of virgin argan oil. A total of 22 samples from Morocco were analyzed. Total polyphenol content ranged between 6.07 and 152.04 mg GAE/kg. Total tocopherols varied between 427.0 and 654.0 mg/kg, being γ‐tocopherol the major fraction (84.68%); α‐, β‐, and δ‐tocopherols represent 7.75, 0.33, and 7.29%, respectively. No influence of oil extraction method on total tocopherols was observed. The AC of argan virgin oils determined by the ABTS method in n‐hexane oils dilution ranged between 14.16 and 28.02 mmol Trolox/kg, and by the ABTS, DPPH, and FRAP methods in methanolic oil extracts between 2.31–14.15, 0.19–0.87, and 0.62–2.32 mmol Trolox/kg, respectively. A high correlation was found between ABTS and DPPH methods applied to a methanolic oil extract. Virgin argan oil presents a higher polyphenol and tocopherol content, and total AC than other edible vegetable oils.     

开封产3种白色菊花提取物的抗氧化活性

采用清除二苯代苦味肼基(DPPH)自由基、清除[2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基及铁离子还原/抗氧化能力(FRAP)测定法,对开封产的3种白色菊花(兼六香白、国华万胜及白玉带)不同溶剂提取物的体外抗氧化活性进行了评价,将所测定结果与水溶性维生素E(6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid,Trolox)及阳性对照二丁基羟基甲苯(BHT)进行了比较。结果表明,3种菊花的不同溶剂提取物抗氧化活性不同。同一种菊花的甲醇提取物具有很好清除DPPH自由基和还原铁离子的能力,而石油醚提取物几乎无活性。菊花的3个品种中,兼六香白和国华万胜的抗氧化活性较好,其活性远远超过白玉带的抗氧化活性。9个提取物中,兼六香白的甲醇提取物总的抗氧化活性最好。它对DPPH自由基的清除能力(IC50值为20.49 mg/L)比BHT(IC50值为18.92 mg/L)作用略低;其还原Fe3+的能力(FRAP值为731.73±1.77μmol TE/g)比BHT(1 581.68±97.41μmol TE/g)作用低1/2。3种方法测定结果基本一致,其中以DPPH法和FRAP法相关性最好(R=0.982 0)。     

核桃仁抗氧化活性研究

采用清除二苯代苦味肼基(DPPH)自由基、清除[2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基及铁离子还原/抗氧化能力(FRAP)测定法,对核桃仁提取物进行抗氧化活性评价,并与阳性对照没食子酸丙酯(PG)、丁基羟基茴香醚(BHA)和二丁基羟基甲苯(BHT)进行比较。在核桃仁提取物中,乙酸乙酯提取物清除DPPH和ABTS自由基的能力(IC50值分别为1.58 mg/L和1.69 mg/L)强于BHA(IC50值分别为3.43 mg/L和1.72 mg/L)和BHT(IC50值分别为18.79 mg/L和6.04 mg/L),弱于PG(IC50值分别为0.86 mg/L和0.66 mg/L);乙酸乙酯提取物还原Fe3+的能力最强〔FRAP值为(13212.99±55.35)μmol TE/g〕,强于PG〔FRAP值为(10617.75±138.38)μmol TE/g〕、BHA〔FRAP值为(7383.10±121.08)μmol TE/g〕和BHT〔FRAP值为(1748.49±3.46)μmol TE/g〕;核桃仁正丁醇提取物清除DPPH和ABTS自由基的能力(IC50值分别为4.94和1.90 mg/L)以及还原Fe3+的能力〔FRAP值为(2299.99±27.68)μmol TE/g〕强于BHT。结果表明,核桃仁乙酸乙酯和正丁醇提取物都具有很好的抗氧化活性,且乙酸乙酯提取物活性强于正丁醇提取物。     

珍珠菜的抗氧化活性

用清除二苯代苦味肼基自由基、清除2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)自由基和铁离子还原/抗氧化能力测定法,分析了珍珠菜提取物总的抗氧化作用。在珍珠菜提取物中,甲醇提取物清除二苯代苦味肼基自由基能力(IC50值为12.28mg/L)比阳性对照BHT作用强(IC50值为18.79mg/L);甲醇提取物对清除2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)自由基能力(IC50值为7.52mg/L)比BHT(IC50值为6.04mg/L)清除能力略低;甲醇提取物还原Fe3+的能力(FRAP值为1179.40±46.70μmolTE/g)比BHT(FRAP值为1748.49±3.46μmolTE/g)略低。珍珠菜3种提取物中,甲醇提取物具有较高的抗氧化能力。该文报告工作的新颖性,已为河南省医学情报研究所2008年5月30日出具的第2008113号《科技查新报告》所证实。     

粘毛蓼的抗氧化活性

用清除二苯代苦味酰基(DPPH)自由基、清除[2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐](ABTS)自由基和铁离子还原/抗氧化能力(FRAP)测定法,对粘毛蓼体外总抗氧化活性进行了评价,结果与6-羟基-2,5,7,8-四甲基苯并二氢吡喃-2-羧酸(Trolox)及阳性对照丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)比较发现,粘毛蓼提取物有很好的体外抗氧化活性。乙酸乙酯提取物清除DPPH自由基(IC50=7.89 mg/L)的能力比BHT清除能力(IC50=18.71 mg/L)强,比BHA(IC50=3.20 mg/L)清除能力略弱;清除ABTS自由基能力(IC50=6.67 mg/L)比BHT(IC50=7.72 mg/L)清除能力强,比BHA(IC50=1.88 mg/L)清除能力弱;还原Fe3+的能力〔FRAP=(1362.55±47.22)μmol TE/g〕比BHT〔FRAP=(1581.68±97.41)μmol TE/g〕略低。在3种提取物中,乙酸乙酯提取物具有最高的抗氧化能力,甲醇提取物次之。3种方法中,DPPH方法和ABTS方法相关性最高(R=0.993)。     

拳参抗氧化活性研究

用清除二苯代苦味酰基（DPPH）自由基、2,2’-连氨-（3-乙基苯并噻唑啉-6-磺酸）二氨盐（ABTS）自由基和铁离子还原／抗氧化能力（FRAP）测定法对拳参体外总抗氧化活性进行评价．并与6-羟基-2,5,7,8-四甲基苯并二氢吡喃-2-羧酸（Trolox）及阳性对照二丁基羟基甲苯（BHT）比较。发现拳参有较好的体外抗氧化活性。甲醇提取物清除DPPH自由基（IC50=3．81μg／mL）的能力远远强于BHT的清除能力（IC50=18．71μg／mL）;清除ABTS自由基能力（IC50=7．65μg／mL）强于BHT（IC50=7．72μg／mL）的清除能力;还原Fe^3＋的能力（FRAP=2009．51±16．44μmol TE／g）最强,强于BHT（FRAP=1581．68±97．41μmol TE／g）。在3种提取物中,甲醇提取物具有最高的抗氧化能力,乙酸乙酯提取物次之。3种方法中,ABTS方法和FRAP方法相关性（R=0．984）最高。     

Comparison between conventional and ultrasound-assisted extractions of natural antioxidants from walnut green husk

Agricultural industries produce substantial quantities of phenolic-rich by-products, which have gained much attention due to their antioxidant properties. Ultrasonic technology was applied for extraction of antioxidants from the walnut green husk using ethanol as a food grade solvent. Response surface methodology (RSM) was used to optimize experimental conditions. The responses were total phenolic content (TPC), ferric reducing antioxidant power (FRAP), scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and yield. TPC varied from 6.28 to 7.23mg GA g^?1 dry sample. FRAP and DPPH values varied from 0.33 to 0.46 mmol Fe²⁺ g^?1 of dry sample and 33.98% to 56.31% inhibition, respectively. Extraction yields ranged from 33.04% to 38.72%. The optimal conditions were 60% ethanolwater mixture as solvent, temperature of 60 °C and extraction time of 30 min. Comparison of ultrasonic-assisted extraction (UAE) and conventional extraction was shown that TPC, FRAP, DPPH and yield obtained by UAE during 30 min were significantly higher than by conventional extraction during 16 hours. The extract can be used as substitute of synthetic antioxidants for food products, color and oxidative stabilization.     

Lipid characterization and antioxidant status of the seeds and meals of Camelina sativa and flax

Four different antioxidant activity assays including 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and oxygen radical absorption capacity (ORAC), and thiobarbituric acid reactive substances were performed on the methanolic and ethyl acetate extracts of Camelina seeds (CS), flaxseeds (FS), Camelina meal low fat (CMLF, 9.9% fat), Camelina meal high fat (CMHF, 24.6% fat), and flaxseed meal (FSM, 2.7% fat). In addition, the fatty acid profile, and phenolic, tocopherol, flavonoid, and glucosinolate contents of CS, FS, CMLF, CMHF, and FSM were studied. The major fatty acid was α‐linolenic acid (C18:3 n‐3) which was 33.2, 29.4, 30.2, 60.1, and 39.3% in CS, CMLF, CMHF, FS, and FSM, respectively. The methanolic extract of CMLF showed the highest values of ABTS, DPPH and FRAP and the highest content of phenolic compounds, flavonoids, and glucosinolates. The methanolic and ethylacetate extracts of CMHF showed the highest values for ORAC and α‐ and γ‐tocopherols. The ethylacetate extracts of seeds and meals of Camelina sativa and flax showed lower values for antioxidant activity, phenolic compounds, and flavonoids than the methanolic extracts. In general, Camelina and FS meals showed higher antioxidant activities, and phenolic and flavonoid contents than their respective seeds. Practical applications: Camelina sativa seeds (CS) and flaxseeds (FS) are rich sources of omega 3 oils. Their by‐products after oil extraction are an attractive source of proteins, lipids, fiber, and natural bioactive compounds such as antioxidants. These by‐products may be used to improve nutritional value and prevent lipid oxidation in feed or food systems.     

Spectrophotometric Determination of Phenolic Antioxidants in the Presence of Thiols and Proteins

Development of easy, practical, and low-cost spectrophotometric methods is required for the selective determination of phenolic antioxidants in the presence of other similar substances. As electron transfer (ET)-based total antioxidant capacity (TAC) assays generally measure the reducing ability of antioxidant compounds, thiols and phenols cannot be differentiated since they are both responsive to the probe reagent. In this study, three of the most common TAC determination methods, namely cupric ion reducing antioxidant capacity (CUPRAC), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt/trolox equivalent antioxidant capacity (ABTS/TEAC), and ferric reducing antioxidant power (FRAP), were tested for the assay of phenolics in the presence of selected thiol and protein compounds. Although the FRAP method is almost non-responsive to thiol compounds individually, surprising overoxidations with large positive deviations from additivity were observed when using this method for (phenols + thiols) mixtures. Among the tested TAC methods, CUPRAC gave the most additive results for all studied (phenol + thiol) and (phenol + protein) mixtures with minimal relative error. As ABTS/TEAC and FRAP methods gave small and large deviations, respectively, from additivity of absorbances arising from these components in mixtures, mercury(II) compounds were added to stabilize the thiol components in the form of Hg(II)-thiol complexes so as to enable selective spectrophotometric determination of phenolic components. This error compensation was most efficient for the FRAP method in testing (thiols + phenols) mixtures.     

Comparison of Two Analytical Methods for Assessing Antioxidant Capacity of Rapeseed and Olive Oils

The oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) methods were used for the determination of antioxidant capacities (AC) of rapeseed oils at different steps of technological process and olive oils. The mean ORAC and FRAP results obtained for rapeseed oils (1,106–160 and 552–95.6 μmol TE/100 g) were higher than for olive oils (949–123 and 167–32.1 μmol TE/100 g). Although, FRAP values were lower than ORAC values for all studied oils, there is a linear and significant correlation between these two analytical methods (r = 0.9665 and 0.9298, P < 0.0005) for rapeseed and olive oils, respectively). Also, total phenolic compounds in rapeseed oils and olives correlated with antioxidant capacities (correlation coefficient ranged between 0.9470 and 0.8049). The refining process of rapeseed oils decreased the total phenolics content and antioxidant capacities by about 80%.     

Optimization of extraction parameters of bioactive components from defatted marigold (Tagetes erecta L.) residue using response surface methodology

Response surface methodology (RSM) was used to estimate the optimum extraction parameters, in which the antioxidant activity (AA) of the extract from the defatted marigold residue was the strongest. The AA of marigold extracts was investigated by the radical scavenging activity assays ((2,2-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH)). Results demonstrated that AA was significantly affected by the content of total phenolics (TP) and total flavonoids (TFA) (p < 0.0001). The optimal extraction parameters of marigold extracts for the highest AA by ABTS method were ethanol concentration of 79.7%, extraction temperature of 74.2 °C and time of 8.1 h, and by DPPH assay with 89.3% of ethanol concentration at 81.5 °C for 11.1 h, AA values were 2.42 and 1.86 mmol TE/g, respectively.     

Effect of extraction conditions on total phenolic content and antioxidant capacity of pretreated wild Peumus boldus leaves from Chile

We studied the effect of both heat-drying and freeze-drying on the recovery of total phenolic compounds (TPCs) and antioxidant capacity from leaves of Peumus boldus Molina (Boldo), an endemic tree of Chile, using DPPH (2,2-diphenyl-1-picrylhydrazyl radical scavenging), FRAP (ferric reducing antioxidant power) and ORAC (oxygen radical absorbance capacity) methods. The results indicated that infusions prepared using commercial boldo tea bags had similar or higher TPCs, DPPH, FRAP and ORAC values in comparison with those of the infusions prepared using heat- or freeze-dried leaves. The extraction experiments showed that hydro-alcoholic mixtures are the best solvents to extract antioxidants from boldo leaves, favoring the use of freeze-dried leaves. Considering the alkaloid profile of the extracts of freeze-dried leaves and herbal tea bags, the latter exhibited higher amounts of the alkaloids tested, including boldine, which is well correlated with the results obtained using the ORAC method. These results indicate a great potential to develop commercial boldo extracts and could encourage improved applications of this endemic Chilean plant.     

Primary Metabolites and Polyphenols in Rapeseed (Brassica napus L.) Cultivars in China

Defatted meals of 10 rapeseed (Brassica napus L.) varieties were investigated for their total phenolic, phenolic acid (free, esterified, and insoluble-bound forms), and tannin contents. The antioxidant capacities (AC) of methanol extracts from samples were assessed using the 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH•), Folin–Ciocalteu method and ferric reducing antioxidant power (FRAP), and β-carotene–linoleic acid tests. In the fraction of free phenolic acids, sinapic, caffeic, ferulic, syringic, gallic, and p-coumaric acids were identified. In the fraction of esterified phenolic acids, sinapine, sinapoyl glucoside, and disinapoyl gentiobiose were identified. After basic hydrolysis, sinapic, ferulic, cinnamic, and 4-hydroxybenzoic acids were identified, and sinapic acid (SA) constituted 98.3% to 99.6% of the total esterified phenolic acids. Eleven components (sinapic, protocatechuic, p-coumaric, syringic, vanillic, gallic, caffeic, ferulic, salicylic, cinnamic, and 4-hydroxybenzoic acids) in the fraction of insoluble-bound phenolic acids were identified. The AC of the samples correlated with the total phenolic content. Overall, the total phenolics showed a better correlation with AC than the individual phenolic compounds. Moreover, SA, sinapoyl glucoside, and disinapoyl gentiobiose showed a highly significant and strong positive correlation with the AC of rapeseed meals, and the derivatives of cinnamic acid showed a higher correlation with AC than the derivatives of benzoic acid. The change in the canolol content in rapeseeds under microwave irradiation is discussed. The correlation of the canolol formed with SA and its derivatives is discussed.     

Antioxidant properties of compounds isolated from wood vinegar by activity-guided and pH-gradient extraction

The chemical profile of wood vinegar (WV) was studied by gas chromatography-mass spectrometry (GC/MS), and 48 organic compounds were identified, including phenols which accounted for 2.0%. Antioxidant compounds were isolated from WV by an activity-guided isolation method for further investigation. The dichloromethane extract from WV exhibited the highest total phenolic content and demonstrated more potent antioxidant activity than the other extracts. Then, the phenols were enriched by pH gradient extraction method from the dichloromethane extract. Seven phenols were isolated from the WV using a sequence of column chromatographic purification steps over silica gel and C18 column, followed by semi-preparative HPLC and their structures were identified by ¹H NMR and ¹³C NMR spectra. All the compounds showed potent antioxidant activities in the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline- 6-sulphonic acid (ABTS), and ferric-reducing antioxidant power (FRAP) assays. This study demonstrates that phenols isolated from WV have the potential to be used as antioxidant agents.     

Mulberry Seed Oil: a Rich Source of δ‐Tocopherol

In the present study, mulberry seed oil (MSO) samples obtained from seeds of different mulberry varieties as well as concentrated mulberry juice production waste (mulberry pomace) were investigated. Radical scavenging capacity, tocopherol and total phenolic content of MSO were determined. It was observed that MSO contain unique amounts of δ‐tocopherol varying between 1645–2587 mg kg^?1 oil depending on the variety. The secondary tocopherol homologue was γ‐tocopherol within a concentration range of 299–854 mg kg^?1 oil. MSO exhibited a very high antioxidant capacity varying in the range of 1013–1743 and 2574–4522 mg α‐tocopherol equivalents (α‐TE) per kg of oil for 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and freeze‐dried 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) (FD‐ABTS) radical cation assays, respectively. Both antioxidant capacity and total phenolic content were higher for mulberry pomace oil compared with the seed oils. Fatty acid composition of MSO was also determined, and linoleic acid was found to be the primary fatty acid (66–80 %).     

山楂提取物的体外和体内抗氧化作用

采用ABTS清除2,2′-连氨-(3-乙基苯并噻唑啉-6-磺酸)二氨盐自由基、FRAP(铁离子还原/抗氧化能力测定法)和DPPH(清除二苯代苦味肼基自由基)三种体外模型筛选山楂提取物抗氧化活性;用高脂高糖乳剂建立了小鼠髙脂质模型,考察了提取物的体内抗氧化效果。山楂提取物体外ABTS、FRAP和DPPH法清除自由基能力测定结果显示,SC>SD>SB>SE>SA,SC在体内可以明显升高SOD(超氧化物歧化酶)水平(P<0.05)和降低MDA(丙二醛)水平(P<0.001)。研究结果表明,SC体外筛选抗氧化效果最好,与体内作用一致,SC体外抗氧化和体内抗脂质过氧化存在一定的相关性。     

Microwave-assisted extraction as an advanced technique for optimization of saponin yield and antioxidant potential from Phyllanthus amarus

The objective of this study was to apply microwave-assisted extraction (MAE) as an advanced technique for optimization of saponin yield and antioxidant potential from Phyllanthus amarus. The findings indicated that the optimal MAE parameters consisted of 100% methanol, irradiation time 4 s/min, extraction time 50 min, and solvent to sample ratio 50 mL/g. Under these optimal parameters, saponin content (SC), saponin extraction efficiency (SEE), and total phenolic content (TPC) of P. amarus were 229.5 mg escin equivalents (EEs)/g dried sample, 82.8%, and 40.7 mg gallic acid equivalents (GAEs)/g dried sample, respectively. The antioxidant capacity of P. amarus in terms of 2,2ˊ-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging capacity (ARSC), 2,2-diphenyl-1-picryl-hydrazil radical scavenging capacity (DRSC), and ferric reducing antioxidant power (FRAP) were 487.3, 330.6, and 233.5 mg trolox equivalents (TEs)/g dried sample, respectively. These measured values were not significantly different from the predicted values by response surface methodology (227.9 mg EE/g dried sample, 82.1%, and 39.2 mg GAE/g dried sample for SC, SEE, and TPC and 484.8, 297.3, and 226.6 mg TE/g dried sample for ARSC, DRSC, and FRAP, respectively). Hence, the optimal MAE parameters are suggested for effective extraction of saponins from P. amarus for further investigations and applications.